As I recently reported in the Guardian, the NSA has secret servers on the Internet that hack into other computers, codename FOXACID. These servers provide an excellent demonstration of how the NSA approaches risk management, and exposes flaws in how the agency thinks about the secrecy of its own programs.
Here are the FOXACID basics: By the time the NSA tricks a target into visiting one of those servers, it already knows exactly who that target is, who wants him eavesdropped on, and the expected value of the data it hopes to receive. Based on that information, the server can automatically decide what exploit to serve the target, taking into account the risks associated with attacking the target, as well as the benefits of a successful attack.